def handle(self, namespace, hash_key):
"""Handles this request."""
# Extract relevant request parameters.
expiration_ts = self.request.get('x')
item_size = self.request.get('s')
is_isolated = self.request.get('i')
uploaded_to_gs = self.request.get('g')
signature = self.request.get('sig')
# Build correct signature.
expected_sig = self.generate_signature(
config.settings().global_secret, self.request.method, expiration_ts,
namespace, hash_key, item_size, is_isolated, uploaded_to_gs)
# Verify signature is correct.
if not utils.constant_time_equals(signature, expected_sig):
return self.send_error('Incorrect signature.')
# Convert parameters from strings back to something useful.
# It can't fail since matching signature means it was us who generated
# this strings in a first place.
expiration_ts = int(expiration_ts)
item_size = int(item_size)
is_isolated = bool(int(is_isolated))
uploaded_to_gs = bool(int(uploaded_to_gs))
# Verify signature is not yet expired.
if time.time() > expiration_ts:
return self.send_error('Expired signature.')
if uploaded_to_gs:
# GS upload finalization uses empty POST body.
assert self.request.method == 'POST'
if self.request.headers.get('content-length'):
return self.send_error('Expecting empty POST.')
content = None
else:
# Datastore upload uses PUT.
assert self.request.method == 'PUT'
if self.request.headers.get('content-length'):
content = self.request.body
else:
content = ''
# Info about corresponding GS entry (if it exists).
gs_bucket = config.settings().gs_bucket
key = model.entry_key(namespace, hash_key)
# Verify the data while at it since it's already in memory but before
# storing it in memcache and datastore.
if content is not None:
# Verify advertised hash matches the data.
try:
hex_digest, expanded_size = hash_content(content, namespace)
if hex_digest != hash_key:
raise ValueError(
'Hash and data do not match, '
'%d bytes (%d bytes expanded)' % (len(content), expanded_size))
if expanded_size != item_size:
raise ValueError(
'Advertised data length (%d) and actual data length (%d) '
'do not match' % (item_size, expanded_size))
except ValueError as err:
return self.send_error('Inline verification failed.\n%s' % err)
# Successfully verified!
compressed_size = len(content)
needs_verification = False
else:
# Fetch size of the stored file.
file_info = gcs.get_file_info(gs_bucket, key.id())
if not file_info:
# TODO(maruel): Do not fail yet. If the request got up to here, the file
# is likely there but the service may have trouble fetching the metadata
# from GS.
return self.send_error(
'File should be in Google Storage.\nFile: \'%s\' Size: %d.' %
(key.id(), item_size))
compressed_size = file_info.size
needs_verification = True
# Data is here and it's too large for DS, so put it in GS. It is likely
# between MIN_SIZE_FOR_GS <= len(content) < MIN_SIZE_FOR_DIRECT_GS
if content is not None and len(content) >= MIN_SIZE_FOR_GS:
if not gcs.write_file(gs_bucket, key.id(), [content]):
# Returns 503 so the client automatically retries.
return self.send_error(
'Unable to save the content to GS.', http_code=503)
# It's now in GS.
uploaded_to_gs = True
# Can create entity now, everything appears to be legit.
entry = model.new_content_entry(
key=key,
is_isolated=is_isolated,
compressed_size=compressed_size,
expanded_size=-1 if needs_verification else item_size,
is_verified = not needs_verification)
# If it's not in GS then put it inline.
if not uploaded_to_gs:
assert content is not None and len(content) < MIN_SIZE_FOR_GS
entry.content = content
# Start saving *.isolated into memcache iff its content is available and
# it's not in Datastore: there's no point in saving inline blobs in memcache
# because ndb already memcaches them.
memcache_store_future = None
if (content is not None and
entry.content is None and
entry.is_isolated and
entry.compressed_size <= model.MAX_MEMCACHE_ISOLATED):
memcache_store_future = model.save_in_memcache(
namespace, hash_key, content, async=True)
try:
# If entry was already verified above (i.e. it is a small inline entry),
# store it right away, possibly overriding existing entity. Most of
# the time it is a new entry anyway (since clients try to upload only
# new entries).
if not needs_verification:
entry.put()
else:
# For large entries (that require expensive verification) be more
# careful and check that it is indeed a new entity. No need to do it in
# transaction: a race condition would lead to redundant verification
# task enqueued, no big deal.
existing = entry.key.get()
if existing:
if existing.is_verified:
logging.info('Entity exists and already verified')
else:
logging.info('Entity exists, but not yet verified')
else:
# New entity. Store it and enqueue verification task, transactionally.
task_queue_host = utils.get_task_queue_host()
def run():
entry.put()
taskqueue.add(
url='/internal/taskqueue/verify/%s' % entry.key.id(),
queue_name='verify',
headers={'Host': task_queue_host},
transactional=True)
datastore_utils.transaction(run)
# TODO(vadimsh): Fill in details about the entry, such as expiration time.
self.send_json({'entry': {}})
# Log stats.
where = 'GS; ' + 'inline' if entry.content is not None else entry.key.id()
stats.add_entry(stats.STORE, entry.compressed_size, where)
finally:
# Do not keep dangling futures. Note that error here is ignored,
# memcache is just an optimization.
if memcache_store_future:
memcache_store_future.wait()
def post(self, namespace, hash_key):
entry = model.entry_key(namespace, hash_key).get()
if not entry:
logging.error('Failed to find entity')
return
if entry.is_verified:
logging.warning('Was already verified')
return
if entry.content is not None:
logging.error('Should not be called with inline content')
return
# Get GS file size.
gs_bucket = config.settings().gs_bucket
gs_file_info = gcs.get_file_info(gs_bucket, entry.key.id())
# It's None if file is missing.
if not gs_file_info:
# According to the docs, GS is read-after-write consistent, so a file is
# missing only if it wasn't stored at all or it was deleted, in any case
# it's not a valid ContentEntry.
self.purge_entry(entry, 'No such GS file')
return
# Expected stored length and actual length should match.
if gs_file_info.size != entry.compressed_size:
self.purge_entry(entry,
'Bad GS file: expected size is %d, actual size is %d',
entry.compressed_size, gs_file_info.size)
return
save_to_memcache = (
entry.compressed_size <= model.MAX_MEMCACHE_ISOLATED and
entry.is_isolated)
expanded_size = 0
digest = model.get_hash_algo(namespace)
data = None
try:
# Start a loop where it reads the data in block.
stream = gcs.read_file(gs_bucket, entry.key.id())
if save_to_memcache:
# Wraps stream with a generator that accumulates the data.
stream = Accumulator(stream)
for data in model.expand_content(namespace, stream):
expanded_size += len(data)
digest.update(data)
# Make sure the data is GC'ed.
del data
# Hashes should match.
if digest.hexdigest() != hash_key:
self.purge_entry(entry,
'SHA-1 do not match data (%d bytes, %d bytes expanded)',
entry.compressed_size, expanded_size)
return
except gcs.NotFoundError as e:
# Somebody deleted a file between get_file_info and read_file calls.
self.purge_entry(entry, 'File was unexpectedly deleted')
return
except (gcs.ForbiddenError, gcs.AuthorizationError) as e:
# Misconfiguration in Google Storage ACLs. Don't delete an entry, it may
# be fine. Maybe ACL problems would be fixed before the next retry.
logging.warning(
'CloudStorage auth issues (%s): %s', e.__class__.__name__, e)
# Abort so the job is retried automatically.
return self.abort(500)
except (gcs.FatalError, zlib.error, IOError) as e:
# ForbiddenError and AuthorizationError inherit FatalError, so this except
# block should be last.
# It's broken or unreadable.
self.purge_entry(entry,
'Failed to read the file (%s): %s', e.__class__.__name__, e)
return
# Verified. Data matches the hash.
entry.expanded_size = expanded_size
entry.is_verified = True
future = entry.put_async()
logging.info(
'%d bytes (%d bytes expanded) verified',
entry.compressed_size, expanded_size)
if save_to_memcache:
model.save_in_memcache(namespace, hash_key, ''.join(stream.accumulated))
future.wait()
def post(self, namespace, hash_key):
original_request = self.request.get('req')
entry = model.get_entry_key(namespace, hash_key).get()
if not entry:
logging.error('Failed to find entity\n%s', original_request)
return
if entry.is_verified:
logging.warning('Was already verified\n%s', original_request)
return
if entry.content is not None:
logging.error('Should not be called with inline content\n%s',
original_request)
return
# Get GS file size.
gs_bucket = config.settings().gs_bucket
gs_file_info = gcs.get_file_info(gs_bucket, entry.key.id())
# It's None if file is missing.
if not gs_file_info:
# According to the docs, GS is read-after-write consistent, so a file is
# missing only if it wasn't stored at all or it was deleted, in any case
# it's not a valid ContentEntry.
self.purge_entry(entry, 'No such GS file\n%s', original_request)
return
# Expected stored length and actual length should match.
if gs_file_info.size != entry.compressed_size:
self.purge_entry(
entry,
'Bad GS file: expected size is %d, actual size is %d\n%s',
entry.compressed_size, gs_file_info.size, original_request)
return
save_to_memcache = (
entry.compressed_size <= model.MAX_MEMCACHE_ISOLATED
and entry.is_isolated)
expanded_size = 0
digest = hashlib.sha1()
data = None
try:
# Start a loop where it reads the data in block.
stream = gcs.read_file(gs_bucket, entry.key.id())
if save_to_memcache:
# Wraps stream with a generator that accumulates the data.
stream = Accumulator(stream)
for data in model.expand_content(namespace, stream):
expanded_size += len(data)
digest.update(data)
# Make sure the data is GC'ed.
del data
# Hashes should match.
if digest.hexdigest() != hash_key:
self.purge_entry(
entry, 'SHA-1 do not match data\n'
'%d bytes, %d bytes expanded, expected %d bytes\n%s',
entry.compressed_size, expanded_size, entry.expanded_size,
original_request)
return
except gcs.NotFoundError as e:
# Somebody deleted a file between get_file_info and read_file calls.
self.purge_entry(entry, 'File was unexpectedly deleted\n%s',
original_request)
return
except (gcs.ForbiddenError, gcs.AuthorizationError) as e:
# Misconfiguration in Google Storage ACLs. Don't delete an entry, it may
# be fine. Maybe ACL problems would be fixed before the next retry.
logging.warning('CloudStorage auth issues (%s): %s',
e.__class__.__name__, e)
# Abort so the job is retried automatically.
return self.abort(500)
except (gcs.FatalError, zlib.error, IOError) as e:
# ForbiddenError and AuthorizationError inherit FatalError, so this except
# block should be last.
# It's broken or unreadable.
self.purge_entry(entry, 'Failed to read the file (%s): %s\n%s',
e.__class__.__name__, e, original_request)
return
# Verified. Data matches the hash.
entry.expanded_size = expanded_size
entry.is_verified = True
future = entry.put_async()
logging.info('%d bytes (%d bytes expanded) verified\n%s',
entry.compressed_size, expanded_size, original_request)
if save_to_memcache:
model.save_in_memcache(namespace, hash_key,
''.join(stream.accumulated))
future.wait()
